Occurrence of Pennate
diatoms (Bacillariopyta) in the Punjab and N.
Similar to our findings, they reported that pennate
diatoms were the dominant group.
Antarctica's waters contain centric forms, such as Actinocyclus (upper photo) and Coscinodiscus (middle photo), and pennate
ones, such as Nitzschia kerguelensis (bottom photo), which is normally found in colonies of individuals joined at the flat face of the frustule, as shown by the three specimens in the photo.
1 cm), dominated by pennate
diatoms, on the underside of the ice at the ice-seawater interface (Horner, 1976; Alexander, 1981; Alexander and Chapman, 1981; Cota et al.
This surface layer was composed primarily of pennate
diatoms, and it appeared to result largely from the sloughing off of periphyton from the sides of the mesocosms rather than from material produced at the water surface.
costatus and the pennate
diatom Asterionellopsis glacialis appeared as the main species responsible for the spring and autumn peaks, respectively (Fig.
Like those in Antarctic sponges, most heterotrophic diatoms are pennate
and occur in benthic habitats, where light is absent or limited and organic substrates are in great supply; such habitats strongly favor heterotrophic growth .
Diatoms were more abundant than in the deep enclosures and included pennate
The most abundant pennate
diatoms encountered were: Nitzschia palae and Synedra ulna, according with the observations made by Adesalu et al.
A further examination of the diatom community showed that both centric and pennate
diatoms increased from low- to high-nitrogen estuaries ([ILLUSTRATION FOR FIGURE 1C OMITTED]; ANOVA, P [less than] 0.
The index includes only those diatoms (89 centric and 186 pennate
species), dinoflagellates (eight naked and 154 thecate species) and coccol- ithophores (24 especies) for which formal diagnosis and illustrations (drawings and/or photographs) have been reported in the scientific literature (journals and/or first degree of master's theses).
Amphora coffeaeformis is a common benthic marine pennate
diatom (Round et al.